Co添加对Fe-Si基合金微波吸收性能影响研究

Effect of Co on Microwave Absorbing Properties of Fe-Si Alloy

为研制低频效应和宽频特性较好的吸波材料,以高纯块状Co、Fe、Si为原料,采用电弧熔炼和高能球磨工艺制备CoxFe80-xSi20(x=0,10,20,30)合金粉体,使用SEM、XRD和矢量网络分析仪等测试手段,研究了合金粉体形貌、结构及Co添加对合金吸波性能的影响。结果表明:制备的合金粉体主要由α-Fe相组成;Co的添加使Co-Fe-Si合金的反射率峰值变小,并随α-Fe晶粒尺寸增大而向低频移动;在涂层厚度为1.8mm的条件下,x=20的合金吸收峰频率和峰值分别为4.8GHz和-13.4dB,低频效应较好,x=10的合金吸波峰频率和峰值分别为6.2GHz和-14.8dB,低于-5dB的吸波带宽达14GHz,具有良好的吸波宽频效应。系统研究了Co10Fe70Si20合金的反射率随涂层厚度变化的规律,结果表明随着涂层厚度的增加,合金的反射率峰值向低频移动,当涂层厚度为3mm时,反射率峰值达到极值,即在3.7GHz处达到-14.8dB。

In order to develop low-frequency effect and wide-frequency characteristic absorbing materials, CoxFe80-xSi20（x=0,10,20,30 mol.%）alloy powders were prepared by are melting and high energy ball milling technique with high pure Co.Fe and Si as raw materials. The morphology and phase structure of the powders were analyzed by Scanning electron microscope （SEM） ,X-ray diffraction （XRD） ,and the effect of the Co content on microwave absorbing properties was investigated by vector network analyzer. The results show that,Co-Fe-Si alloy powders are mainly composed of a-Fe phase. The value of the reflectivity peaks reduce with the addition of Co and the reflectivity peak frequency move to low frequency with the grain size of a-Fe increasing. Alloy obtains well low-frequency effect when the addition of Co in the alloy is 20~~. The minimum reflectivity and absorbing peak frequency is --13.4 dB at 4. 8 GHz,while the minimum reflectivity and absorbing peak frequency is --14.8 dB at 6.2 GHz,furthermore the band- width under --5 dB reach 14 GHz,achieving well wide-frequency effect,when the content of Co is 10%. The reflectivity of ColoFeToSizo alloy was systematically studied, the result shows that the reflectivity peak frequency moves to low frequency with the increasing of material thickness. The reflectivity peak is least when the coating thickness is 3 mm,which reaches -14.8 GHz at 3. 7 GHz.